Horn



Dec. 13, 1932. v. w. Busch 1,890,719

norm

Filed July 5, 1928 IN VEN TOR wa s; W

A TTORNE Y Patented Dec. 13, 1932 UNITED STATES PATENT OFFICE VERN W.BUSGH, OF SOUTH BEND, INDIANA HORN . Application filed July 5, 1928.Serial No. 290,557.

This invention relates to horns and paris highly polished and it istherefore, very ticularly to the' class in which sound waves desirableto use because friction is reduced are increased or magnified, theprincipal obto a minimum and the sound waves pass ject being to providesuch a horn which is through the amplifier unhindered. This fealight inweight, compact, strong in constructure allows the sound waves to beproduced tion, and exceptionally economical to manuwith increased volumeand mellowness withfacture. out distortion. Celluloid is a non-metallicAnother object is to provide a horn of the material and a horn built ofthis material will sound amplifying type with a natural highly not emitthe harsh metallic sounds which are polished inner surface wherebyfriction is at so prevalent in some of the other types of I a minimum'sothat the sound waves will loud speakers used in the past. Anotherfeatravel unhindered and will reproduced ture which is highly desirableis that celluwith increased volume without distortion. loid is notporous and will not be affected by Another object is to provide a hornof the dampness or changes in temperature. Many sound amplifying type inwhich sound waves of the horns previously built were of plaster will beproduced in their original rendering of Paris or other porous materialwhich abwith increased volume and will not be afsorbs moisture on dampdays which does not fected by dampness and normal temperature allowmusical notes to be produced with melchan es. lowness and fine qualityof tone. Celluloid A urther object is to provide a horn of the can beproduced in a variety of colors which. T9 sound. amplifying type whichisformed from may match with furniture and the like. An-

celluloid, yralin or similar materials. otherstriking advantage ofcelluloid is that 'A still fiirther objectis to provide a horn it isvery light in weight but is very strong of .the sound amplifying typeformed of two and rigid, therefore making the same very celluloidmembers having convolute grooves desirable to use as it can be carriedfrom place T therein, the members being secured together to placevwithout any great effort. A further with the grooves in matchedrelationship to advantage is that by reason of its lightness provide anamplifying passageway. and narrowness, the horn of my inventionis Thesebeing among the ob]ects of the presreadily adaptable for use inautomobiles ent invention, the same consist of certain feaequipped withradio receiving sets. .5

tures of construction and combinations of In the accompanying drawingwhich ilparts to be hereinafter described with reflustrates a suitableembodiment of the preserence to the accompanying drawing, and cutinvention, then claimed, having the above and other 1 Figure 1 is a sideelevation of the comobjects in View. v p pletely assembled horn mountedupon a suit- I This invention isparticularly adaptable to ablereproducing unit. that type of horn commonly known as a loud Figure 2 isatransverse section through the speaker to increase or amplify thesounds horn taken on the line 22 of Figure 1. transmitted by a radio'orwireless apparatus, Figure 3 is an elevation of one of the horn althoughthe loud speaker is equally as adaptmembers looking toward the convolutegroove. able to produce the sounds produced by a therein showing theoutlet opening. talking machine or other instruments ofthis Figure 4 isan elevation of the other horn character. p member looking toward theconvolute groove The horn is constructed of sheet celluloid therein. 'or.pyralin which is formed to the desired Figure 5 is an enlarged sectiontaken on shape by a process which is the subject matthe line5-5 ofFigure 4 showing the gradual ter of another application. Celluloid hasdecrease in thickness ofthe horn material at many characteristics whichrenders the same points farthest away from the parting plane. verysuitable for a sound amplifying horn, Referring to the accompanyingdrawing in one of whichis that the surface of thesame which likenumerals refer to like parts throughout the several views, the loudspeak-' er or sound amplifier is built up of two sec-' tions 10 and 11,each being formed to shape from a single piece of sheet celluloid ors'imcular groove 12 therein arranged in a spiral form, the samepreferably having at least two complete turns. The groove 12 coilsinwardly in a counter-clockwise direction and gradually increases inwidth as the same ap-d proaches' the center of the section 10. Theentrance to the groove 12 isat the-endhaving thesmallest width and isenlarged at 13 for a purpose to be described later. Similarly thesection 11 is formed to the shape shown in Figure 4 and is provided witha semi-cirfused together,

"cular convolute groove 14 thereinof the same size as thegroove 12 whichcoils inwardly 1n a clockwise direction and gradually increases in widthas the same approaches thecenter 'of the section 11. The entrance to thegroove 14 is enlarged at 15 for a purpose to be described later.

The two sections 10 and 11 are secured together by cementing the webs 16between the turns of the groove 12 to the webs 17 between the spiralturnsof the groove 14. Celluloid 'is capable of being dissolved and forthis reason two celluloid parts can be very efficiently andsatisfactorily secured together by dis- "solving the surfaces andforcing them into contact with each other. In the present invention, thewebs 16 and 17 of the two sections 10 and 11 are coated with acetone orsimilar substance which causes the surfaces thereof to fuse or dissolve.

are then brought into contact with each other When these surfaces are aunder pressure.

a solid unbreakable ]omt is provided which can be compared to a weldedjoint between two pieces of metal.

When the two sections 10 and 11 are secured together in this manner thegrooves 12 and 14 .are in matched relationship and a section thru thesame presents a circular passageway 18 arranged in spiral form as shownin Figure 2.

The passageway 18 is of smalldiameter at its outer end which is thesound inlet and gradually increases in diameter up to the outlet 19which isprovided' for by cutting away a portion of the celluloidcomprising the'end of the groove 12 in the section 10. The enlargedentrances 13 and'15 of the grooves 12 and 14 respectively when combinedprovide a cylindrical opening which receives the'discharge end of areproducing unit 20. The

reproducing unit 20 is mounted upona base block 21 which also providessupport for the sections 10 and 11.

It will be noted in Figure 5 that the celluloidsurrounding the openinggradually decreases in thickness as a chord perpendicular to the planeof separation of the passageway furniture and the like.

These surfaces I 18 increases in length. This-feature increases thequality of the tones produced, since the walls are of greater thicknessadjacent the common plane of the convolute curve than at points farthestaway from this plane.

It is apparent from the foregoing description that a sound amplifierconstructed from cellulose material to the shape shown has manyadvantages over amplifiers used in the past. I

The features which make the amplifier of the present invention moreadvantageous than other types are as follows:

Light in weight, making the same portable and light enoughtohang upon awall without danger of falling; ll

Extremely economical to manufacture as thesame is constructed of onlytwo celluloid sheetsmolded to the proper shape.

Natural extremely smooth passageway surface which reduces friction to aminimum thereby reproducing tones in their original rendering. V

Gradual dec'reasein thickness of thepassageway walls as the chordperpendicular to the convolute plane increases in length, which improvestone qualities. I a

. Extremely compact thereby requiring small mounting space but with anexceedingly long passageway for its size- Adapted to be produced incolors to match Not affected by dampness and normal temperaturequalities thereby giving perfect amplification at all times. 7

It is to be understood that formal changes may be made in the specificembodiment of the invention described without departing from the spiritand substance of the broad invention,the scope of which is commensuratewith the appended claims.

What I claim is 1. A sound'amplifying device constructed ofcelluloid-like material, having a sound amplifying passageway therein ofconvolute form gradually increased in area from the inlet'to the outletthereof, the walls of said passageway being decreased in thickness asthe chord perpendicular to the convolute plane is increased in length. Ip

2. A sound amplifying device comprising two members of celluloid-likematerial secured together, each of said members being formed from asingle sheet of celluloid-like material, and a' continuous soundamplifying passageway between said members, one of saidmembers'having'an outlet opening for said passageway.

3. A sound amplifying device comprising two members of celluloid-likematerial securedtogether having semi-circular grooves therein arrangedin convolute form in matching oppositely-disposed relationship to eachother to provide a circular sound amplifying passageway, an inlet forsaid passageway,

and an outlet for said passageway in one of said members adjacent thecentral axis of said device, said passageway being gradually increasedin area from said inlet to said outlet.

4. A sound amplifying device comprising two members of celluloid-likematerial secured together having semi-circular grooves therein arrangedin convolute form in matchin oppositely-disposed relationship to each oter to provide a circular sound amplifying passageway of increasing areafrom the inlet to the outlet thereof, and sound reproducing mechanismfor said inlet, said outlet for said passageway being formed in one ofsaid members.

5. A sound amplifying device comprising two members of celluloid-likematerial, each having a continuous convolute groove semicircular insection and of gradually decreasing radius, said members being securedto gether with their grooves presented toward each other, therebyforming a convolute smooth-walled passageway of gradually increasingdiameter from the inlet to the outlet for the transmission andamplification of sound waves.

Signed by me at South Bend this 30th day of June, 1928.

VERN W. BUSCH.

